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Archive for June, 2014

A person’s entire immune system can be rejuvenated by fasting for as little as three days as it triggers the body to start producing new white blood cells, a study suggests

Researchers say fasting “flips a regenerative switch” which prompts stem cells to create brand new white blood cells Photo: PEGAZ/Alamy By Sarah Knapton, Science Correspondent
7:51PM BST 05 Jun 2014
Fasting for as little as three days can regenerate the entire immune system, even in the elderly, scientists have found in a breakthrough described as “remarkable”.

Although fasting diets have been criticised by nutritionists for being unhealthy, new research suggests starving the body kick-starts stem cells into producing new white blood cells, which fight off infection.

Scientists at the University of Southern California say the discovery could be particularly beneficial for people suffering from damaged immune systems, such as cancer patients on chemotherapy.

It could also help the elderly whose immune system becomes less effective as they age, making it harder for them to fight off even common diseases.

“It gives the ‘OK’ for stem cells to go ahead and begin proliferating and rebuild the entire system,” said Prof Valter Longo, Professor of Gerontology and the Biological Sciences at the University of California.

“And the good news is that the body got rid of the parts of the system that might be damaged or old, the inefficient parts, during the fasting.

“Now, if you start with a system heavily damaged by chemotherapy or ageing, fasting cycles can generate, literally, a new immune system.”

Prolonged fasting forces the body to use stores of glucose and fat but also breaks down a significant portion of white blood cells.

During each cycle of fasting, this depletion of white blood cells induces changes that trigger stem cell-based regeneration of new immune system cells.

In trials humans were asked to regularly fast for between two and four days over a six-month period.

Scientists found that prolonged fasting also reduced the enzyme PKA, which is linked to ageing and a hormone which increases cancer risk and tumour growth.

“We could not predict that prolonged fasting would have such a remarkable effect in promoting stem cell-based regeneration of the hematopoietic system,” added Prof Longo.

“When you starve, the system tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged,” Dr Longo said.

“What we started noticing in both our human work and animal work is that the white blood cell count goes down with prolonged fasting. Then when you re-feed, the blood cells come back. So we started thinking, well, where does it come from?”

Fasting for 72 hours also protected cancer patients against the toxic impact of chemotherapy.

“While chemotherapy saves lives, it causes significant collateral damage to the immune system. The results of this study suggest that fasting may mitigate some of the harmful effects of chemotherapy,” said co-author Tanya Dorff, assistant professor of clinical medicine at the USC Norris Comprehensive Cancer Center and Hospital.

“More clinical studies are needed, and any such dietary intervention should be undertaken only under the guidance of a physician.”

“We are investigating the possibility that these effects are applicable to many different systems and organs, not just the immune system,” added Prof Longo.

However, some British experts were sceptical of the research.

Dr Graham Rook, emeritus professor of immunology at University College London, said the study sounded “improbable”.

Chris Mason, Professor of Regenerative Medicine at UCL, said: “There is some interesting data here. It sees that fasting reduces the number and size of cells and then re-feeding at 72 hours saw a rebound.

“That could be potentially useful because that is not such a long time that it would be terribly harmful to someone with cancer.

“But I think the most sensible way forward would be to synthesize this effect with drugs. I am not sure fasting is the best idea. People are better eating on a regular basis.”

Dr Longo added: “There is no evidence at all that fasting would be dangerous while there is strong evidence that it is beneficial.

“I have received emails from hundreds of cancer patients who have combined chemo with fasting, many with the assistance of the oncologists.

“Thus far the great majority have reported doing very well and only a few have reported some side effects including fainting and a temporary increase in liver markers. Clearly we need to finish the clinical trials, but it looks very promising.”

Scientists will be ready to create babies from three people in around two years, if it is made legal, a review says.

The technique, using eggs from two women and one man’s sperm, would be used to prevent deadly mitochondrial diseases.

The UK fertility regulator said there was no evidence that it would be unsafe, but called for extra checks.

Changes to fertility regulations are being considered by government.

The illnesses are caused by damage to the tiny power stations in every cell of the body called mitochondria.

One in every 6,500 babies are born with severe mitochondrial disease which means they have insufficient energy to function – it leads to muscle weakness, blindness, heart failure and even death.

Mitochondria are passed only from mother to child.

A scientific panel, assembled by the Human Fertilisation and Embryology Authority (HFEA), assessed two advanced forms of IVF using material from three people – the parents to be and a woman with healthy mitochondria.

1) Two eggs are fertilised with sperm, creating an embryo from the intended parents and another from the donors 2) The pronuclei, which contain genetic information, are removed from both embryos but only the parents’ is kept 3) A healthy embryo is created by adding the parents’ pronuclei to the donor embryo, which is finally implanted into the womb 1) Eggs from a mother with damaged mitochondria and a donor with healthy mitochondria are collected 2) The majority of the genetic material is removed from both eggs 3) The mother’s genetic material is inserted into the donor egg, which can be fertilised by sperm.
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1/2Prof Robin Lovell-Badge, from the Medical Research Council and a member of the scientific panel, said: “The direction of travel still suggests that it is all safe, but we don’t know what’s round the corner so we’re being a little cautious.”

The HFEA report called for a series of final tests before either of the procedures could be performed.

This would include a more detailed assessment of the efficiency of both proposed techniques when using human eggs or embryos.

The risk to the child and any subsequent generations of mutated mitochondria being transferred during the procedure also need to be investigated in more detail.

“I think that [two years] is not a bad estimation. The other sorts of experiments that we thought were necessary, again it will take about two years to complete all of those.”

Prof Andy Greenfield, who chaired the scientific review panel, said safety was “not a straightforward issue”.

He added: “Are these techniques safe in humans? We won’t know that until it’s actually done in humans.

“Until a healthy baby is born we cannot say 100% that these techniques are safe, if you think back to when IVF was a new technology all of these questions were asked before IVF.”

Defective mitochondria leave the body with insufficient energy to function
Mitochondria have their own tiny set of DNA, so any resulting children will have genetic material from three people.

The treatments would class as germ-line therapy, causing changes which would be passed down through the generations.

Ethical concerns have been raised and some campaign groups are worried it could be the thin end of the wedge to genetic modification of people.

‘As soon as we can’

The UK government has in principle backed three-person babies. The chief medical officer, Prof Dame Sally Davies, said last year: “It’s only right that we look to introduce this life-saving treatment as soon as we can.”

This scientific review was commissioned by government as part of a wider consultation. The Department of Health will publish its response to the consultation in the coming months and says a firmer timescale for any regulatory changes will be revealed then.

A spokesperson said: “Mitochondrial donation will give women who carry severe mitochondrial disease the opportunity to have children without passing on devastating genetic disorders.

“It will also keep the UK at the forefront of scientific development in this area.”

Sarah Norcross, the director of the Progress Educational Trust, said: “The scientific review committee have given a considered thumbs up to allowing techniques to avoid the transmission of inherited mitochondrial disease to be used in clinic.

“We therefore urge the Government to press ahead and pass regulations to allow families blighted by mitochondrial disease to benefit as soon as possible.”